The two-volume set 15725 and 15726 constitutes the refereed proceedings of the 23rd Scandinavian Conference on Image Analysis, SCIA 2025, held in Reykjavik, Iceland, during June 23–25, 2025. The 60 revised full papers presented in these proceedings were carefully reviewed and selected from 98 submissions. The papers are organized in the following topical sections: Part I: Machine learning and deep learning; Segmentation, Grouping, and Shape; Vision for robotics and autonomous vehicles; Biometrics, faces, body gestures and pose; 3D vision from multiview and other sensors; and Vision applications and systems. Part II: Datasets and evaluation; Image and video processing, analysis, and understanding; Detection, recognition, classification, and localization in 2D and/or 3D; Medical, biological, and cell microscopy; Explainable AI for CV; Vision + language (+ other modalities); Computational photography; Fairness; and Low·level and physics·based vision.